Method of producing sound-records.



v. H. EMERSom METHoD F Pnopucmc souND RECORDS'.V

APPLICATION FILED IULY 24 1915.

Patented Apr. 1,1919

' Vdtpr' Hugo Emer/'spn inn or dieing out the commercial records'.

` 'nur nn vsfr vieron, nueo EMENSQN, or NNW Yoan, N. Y., assioma' To nMnnsoN, PHONOGRMH co., me., 'A CORPORATION or New Yoan'. f

METHOD or rnonUcrNG Soulan-RECORDS.

. the following specification and the accompanying drawings, forming a part of the saine. f

more particularly to those of the type having grooves with lateral undulations, and has for an object tov provide a method for reproducing with maximum accuracy and i'idelity sound records of the class described.

lnproducmg the commercial form oi suchrecords the usual practiceis to out into a blank of suitable'recordinateriah so called, a groove or grooves having undulations corresponding' to sound Waves, and to make a cmale copy thereof having a raised portion with irregularities corresponding tothose oi improvements in the grooves, which copy is also called 'a matrix, and is in' turn employed in stanip- My process more particularly relates to the Iirst steps referred to, namely.y inpreparin' a built-up record blank 'having its groove tormedin a prescribed manne-r, and employing in connection therewith the usualelectrolytic process with the desired result of 'entirely filling,r out the grooves oi the sound record blank with the elcctrolytic deposit, by means of eliminating; from the Walls thereof the inner lining of conductive material that liar heretofore been used in fniaking electro-matrices.

yse

` with any of the familiar types of recording y In the familiar process of electrolysis, the clectroplate deposit requires an electric con ducting medium, and accordingly I form my record blank with a suitable electro-conduc` tive plate of 'the form of the record required, preferably made ot a sheet oi' hard metal,-

such as-hard brass, upon which as abase, l

lay to the required deptha' coating of suitable record material.

` then'i'orm the usual sound record groove ydevices adapted. to .vibrate laterally, preferably using a stylus having a V-shaped recording point, slightly bluntediand resting upon the underlying electroconductive base which when formed of suiliciently hard metal will resist the cutting tendency of the Spcification of Lettersy Patent.

My invention relates to sound records, 'and' Patented Apr. 1, 1919.

Application rmed July 24, 1915. eria1No.41,635.

stylus While thel record material is being removed thereby. Thus a groove of evendepth will be formed in the/top surface of the record blank having,` lateral undulations correspondingvto the sound Waves recorded. The flat or tablet former' disk is preferably employed in the practice. of my improvedi method of production, to which the rotary" motion isirnparted in thek usual Way 'to form a spiral 'of the sound yrecord groove, the edges of the successi-ve laps thereof being practically contiguous, that is, the width of the Wall separating the vgrooves being reduced to a minimum, allowing only for the irregularities of the undulations thereof. In

thus forming a' sound record groove in `a blank formed 1n the manner described, the

recording'stylus in lcutting the groove re moves the material of. the superimposed layer', therebyexposing for electric contact the electroconductive base, and the record thus prepared is now ready for introduction intoithe electrolytic bath; and in this connection 'it Will be observed that a ggfrocn'evv thus formed for electroplating will be Wholly free from foreign substances, thereby producing an absolutely accurate duplicate of the original. V

For reasons lhereinafter explained more in detail, the groove may be prolonged at both ends, as illustrated in my preferred method, so as to cover substantially the face of the disk which extended portions will have all the charamteristicsl of the sound record groove excepting the undulatory featurethereof-` The foregoing then constitutes the essen f' tial features of the initial steps ofi my processLandr generically described, ythe remining stages relative to the consummation thereof consistin completing the electroplate` `termed as described, which in the usual way is prepared as a. die or male ruatriX for stamping'or imprinting the record thereon intoblanlrs for producing conirneiL cial records. l v I l represent in 'the drawings hereto attacheda portion of the ap aratus and products employed incidentally in the practice of my improved vvprocess, of which Figure 1A is illustrative of a sound record tablet of `the flat rotatable type with a spiral groove covering'the face thereof, a portion having 'lateral undulations; Fig. 2

is an enlarged diainetral sectionalview of a portion of ar recordtabletsimilarjto that therein; this view shows va record ready ior the electroplatin proc'ess on completion groove spiral. ig. 3 is also a kpartial cross struction upon an enlarged scale as in' Fig. 2, showing in part the matrix formed in the electrolytic bath.

4 ,Having reference to the draWings:.The. numeral l represents a sound recordy of the rotatable ydisk typeeomposed of anunderlying base plate 2 preferably made of hard bra-ss,- having upon onejsurface thereof a coating of record material 3 which may be made of any of the well known compositions employed for receivin' and preserving 1mpressions made by t recording stylus,

such as beeswax, parafiin, etc. rThe disk- 1' thus prepared` is rotated at a predeter- Qmined speed While a stylus `5; having its point 5a .cutting entirely through the coat-- mg and resting upon the underlying plate 2, engraves by a suitably'controlled mechanism a spiral form of groove 4c in the face :of record 1, through a Aportion of which the stylus is -caused to vibrate in producing in the usual manner lateral undulations i in the form shown in Fig. 2. The grooves thus. formed bythe stylus as they lapare separated by a' Wall .of slight thickness, and

' latio'ns of contiguous portions of the spiral' in the practice of my invention I find it preferable to provide the Wallbetween the grooves .with a minimum of width consistent with the maximum amplitude of the undu- The slightly blunted point of the stylus thus drawn along and scraping the record material from-the face of the metal base plate of the blank exposes the surface thereof in the process just .described 4as a nely. traced line, formiu the bottom ofthe groove 4. Upon this narrow exposure of the underlying metal surface the electro? plate lwill begin toform bythedeposit thereon of the atoms-of the metal kwhich characterizes the asis. of the Vsolution. c,

Inpractising my invention I preferably use a copper solution, and the minute particles of this metal thus deposited upon a slender zig-zag 4base as abeginning, as the electrolytic process lcontinues are added one uponanother in constantly widening'r layers until the top of tbe groove is reached; as es the deposited metal rises along the wa lso contiguousgrooves and unites .at the'respective top edges` thereof' :to form aucontinuous sheet lof copper electrolyte employed,- technicall known as ions,or-kath1ons, asj they Woud` be more specifically describedv when metallic salts as' at present preferably- Aemployed constitute the 'electroplate 'Thus all v`'portions i of the inall its details the exactm e counterpart 'l0 yof the grooved spiral 4 and which during sectional View giving details of groove conmerely not eleetrolytically deposited upon a` con-v v75 ducting medium overlaid upon and lining said wall surfaces 4b as heretofore employed.

. The r'oove 4 it will be apparent as made in the crm illustrated andicovering'the entire surface of' the record conveniently 80 serves thepurpose of extending the electroplate over the full areaof the record. .On the otherhand, should such an original record be prepared for'the elect-rolytie. process as described herein, except that "a `part 8 5 only of the groove be present, namely, the sound record portion 4 as now usually employed, in that-.case the electro-plate deposited thereon would be limited tothe parthaving the groove spiral, for the reason that the electric current is conducted toward that portion of the record blank.

vSuch an electroplate however would take the form of an annular disk, that is, one hav.-

ing the sound record'complete but without 95 .trolytic vprocess inthe usual Way. But '.ni

either of the proposed methods there would result an unevenness in the superficial plane V105.

of the matrix record thus forn'ed which would entail further eareand 'attention in obviating such irregularity. This'endlfatf taining a most convenient'and satisfactory jmethod a's'described, namely .by continuing 1.10 I the# `roove 4 all' the Way from thecir.- cuni erence to the center. The electroplate is thereupon made of uniform'v thickness throughout ax'idtheelectrodeposit may be f continued until any desired strength of ma- `rterial-isr obtained. w

The matrixv thus deposited in the form of a thin copper sheet may 'be readily sepa-. ratedgfr'om the grooved original orinaster record,'the union between the'raisedportionsv 120 or ridges Tand the baseplate ithef disk 1k being easily broken owing-tothegornparatively small area of contact of the narrowed top portions of the raised spiral landjthe metal platetowhich it adheres. The thus produced-may ther be employedminthe usual mannerI of manuj.

featuring copies" of the original record, that;

had been prepared. in 'accordance with@the#3.

process hereinabove described, freeffm. in'- 13o areararies anavoidabbv due to extmmioas or l obtrueive foreign deposits in the grooves rerordedv therein, with the highly beneficial resultI that an improved record may be formed which vrillwith prartically undiminished fidelity and pr ision reprodme the sounds originally recorded for the pose of manifold reproduction Having described my invention. what l claim ia:

ll. In producing sound records, the herein described method ot' making male matrices which consists ot', first, preparing a blank having an eieetro-comluotive hase and a, layer ot' record material thereon, then making: an original sound rerord by cutting a groove ot uniform depth in said record material by means of a, laterally viln'atile recording stylus and exposing" for eleetrolytie action thesurface oile Said 'base at the bot/tom of the groove thus formed; then forming a matrix thereon by electrolysis; and fina-lll7 separating said matrix from Said basema terial.

purl The procesa ot' produringr Sound records vvhirh consists of first, preparing a rerord blank having' a. taiseportlon ot electro-rondurtire material anda laver ot .fantahle rerkord material euperimpossed thereon; then forming an original Sound record on Said 'blanlr by rut-ting an undulatory xgroove in said superimposed laver and` exposing the nuntaoe o Said base at the bottom of Said nano-.a13 aaid exposed surt'are having nndnlaf tions rorresponding to and representative ot sound vibrations; then i'fa'niingrl a male inatrix thereon by elertrolvnia. and thereupon muploving said matrix t'or reprodurinp; ropies ot' the original sound rec-ord.

3. The provean ot' produeing" sound rerordn ywhich roneiists of tirst, preparing a record blank having a plurality of layers, one of said invern Constitntmgz a base ot' elertro conductive material with another layer snperimpoaed thereon eompriaing a waxflike record materiah then forming an original :mund reco-rd by Hitting; a groove in said superimposed layer having undulationsr con responding to and representative of sound vibrations, and exposingr the surface of said base 'at the bottom of said groove; then formii'lg a male matrix thereon b v elertrolysis; and thereupon en'iploying Said matrix for reproducing copies of the original said record.

4. in producing sound rerords the herein described method of making male matrices which consists of, firstf preparing a. bla-nk havingr an electro-ronductive base and a layer of suitable record material thereon; then cutting a spiral groove of kuniform depth in said record material by means of a laterallj,y vihratile recording stylus eaused to vibrate in rerordiinql Sound Waves within a portion onl \v of :said groove and exposingr thereby for elertrolvtir artiou the surliare of said base at the bottom of th(` groovethns formed; then forming a malt` matrix thireon by electrolyis: and finally separating' said' matrix from Said haar.

ln prodneing` sound rrrordflisk tablets. the herein desvrihed method oi makingr mah1 matrireal whirh consists of, first. preparing a Cirrular blank havingan elentro-rondurtive has@ and a layer ot suitable rerord material thereon.: then rutting by means oi a suitable stylus a spiral groove ot uniform depth in said record material. said spiral extending auhsnmtially over the entire surface of Said blank and eriposing' tor olertrolytir action the `#nriaro of said. base at the bottom ot the groove thus yfoi-aaah musing said Stylusythen forming a matrix thereon h v elertrohVA sis: and finally Separating said matrix from said base. f

In testimony whereof. l have hereunto art nl v hand in the presence of tivo anhsrrihingr Witnesses. :r

VICTOR lill( l() l'ivililON. Writnesn'es:

iVlAx B. ll'lanns, EDWARD B. Manna 

